AIR CONDITIONING SYSTEM

PROBLEM TO BE SOLVED: To provide an air conditioning system having a plurality of heat source machines and capable of utilizing control of the number of the operated heat source machines in minimizing coefficient of evaluation to improve efficiency related to saving of energy consumption.SOLUTION: The air conditioning system controls the number of operated heat source machines for setting the number of a plurality of heat source machines according to loads specified by air conditioning conditions. The control for the number of operated heat source machines includes load correlation operated number setting processing for changing the number of operated heat source machines by determining appropriateness of the number of operated heat source machines in relation to a current load, and evaluation function correlation operated machine number setting processing for obtaining an evaluation function about consumption energy of each of the current number of the operated heat source machines, the increased number of the operated heat source machines, and the decreased number of the operated heat source machines, and changing the number of operated heat source machines to minimize the evaluation function.